This Year's Flu Vaccine Is Only 36% Effective. Why You Should Still Get It

The Centers for Disease Control (CDC) issued its latest flu update on Friday, and it came with some dire-sounding news about this year’s flu vaccine effectiveness. The 2017-2018 flu shot is only 36% effective against influenza A and B, which encompasses H3N2, the problematic flu strain that’s been circulating widely this year.

Here’s the thing: That effectiveness rate is actually better than expected. And public health experts widely agree that you should still get this year’s flu shot if you haven’t.

Why is that? For one thing, seasonal flu vaccine effectiveness tends to oscillate between 40% and 60% in any given year (it’s hard to gauge which strains will be dominant before flu virus activity picks up). So while 36% is a relatively low effectiveness rate, it’s not as bad as some initially thought it would be. Some earlier estimates suggested the figure may wind up closer to 30% or worse.

Furthermore, medical professionals say it’s still worth getting your flu shot even if you may wind up contracting the virus anyways. That’s because the vaccine has protective qualities irrespective of strain. “Getting the flu shot is the same kind of sensible precaution as buckling your seatbelt. If you got the flu shot but you end up catching the flu, it could be less severe and less likely to land you in the hospital,” as Health and Human Services (HHS) Secretary Alex Azar explained to CNN.

The CDC makes similar observations while noting the imperative to create better shots. “Although more effective vaccines are needed, vaccination prevents a substantial burden of influenza-related illness annually,” the agency wrote in its latest flu report. “During the 2014–15 season, when [vaccine effectiveness] against medically attended illness caused by any influenza virus was less than 20%, vaccination was estimated to prevent 11,000–144,000 influenza-associated hospitalizations and 300–4,000 influenza-associated deaths.”

And it’s not too late to get a flu shot even if you’ve already had the flu. You shouldn’t get the vaccine while you’re palpably sick; but getting it can prevent a future infection from a different strain and help protect people who are most at-risk for the virus. Flu season is far from over, and influenza B strains may well start to rise in comparison to the influenza A strains like H3N2.